tests: new test to check that the orphan file is cleaned up

tests: new test to check that the orphan file is cleaned up

This test verifies that e2fsck clears the orphan file if it is present.
The filesystem was created by simply creating a bunch of empty files and,
while those files were open by an application, delete some of them in
order to add them to the orphan file.  After this, the filesystem is
simply powered off.  An e2fsck will need to clear the orphaned inodes but
also to clean the orphan file.

Signed-off-by: Luis Henriques (SUSE) <luis.henriques@linux.dev>
Link: https://lore.kernel.org/r/20240611142704.14307-3-luis.henriques@linux.dev
Signed-off-by: Theodore Ts'o <tytso@mit.edu>